Aafter almost a year of pandemic terror, the end is in sight. But you still have to care.
The FDA has granted emergency use approval for two safe and effective vaccines that science has delivered at record speed. The question now is: How do we best distribute it?
The Advisory Committee on Immunization Practices (ACIP) of the Centers for Disease Control and Prevention (ACS) has published guidelines that vaccinations should start with healthcare professionals and residents of long-term care institutions, followed by other essential frontline workers and those over 75 years of age. How a history of Covid-19 infection is only called a subpriority should have an impact on the place in the queue: ‘HCP with documented acute SARS-CoV-2 infection in the preceding 90 days can choose postpone vaccination until near the end of the 90- day to facilitate the vaccination of those who remain sensitive. ”
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Given the low risk of reinfection and the limited supply of vaccine doses, it would be a mistake not to give previous infection a more important consideration in our vaccination of the vaccine. Since about 75 million Americans are already infected with SARS-CoV-2, but only 24 million know it, the use of large-scale Covid-19 antibody testing can help better target vaccine allocation. By doing so, it can save lives and we can soon become normal again.
This strategy builds on the two biggest discoveries found in efforts against the virus. The first is that after infection, including mild and asymptomatic infections, lasting and strong immunity appears to be up to six plus months. The fact that nearly 100 million cases of Covid-19 have been confirmed worldwide and only a handful of documented reinfections provide compelling evidence of lasting immunity. And even among the rare re-infections, its course is likely to be lighter thanks to the memory of the immune system.
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The second breakthrough is the resounding success of the development of Covid-19 vaccine.
This combination of lasting immunity and effective vaccines has been the cornerstone of almost all viruses’ successes in the past (HIV is by far the most important exception). This is how the plagues of smallpox, polio, measles, mumps and other infectious diseases are beaten. And that’s how we’re going to beat Covid-19.
But even in the best case, it will take months before enough vaccine doses are made to treat everyone. Since epidemiologists estimate that two-thirds of the population must be immune to the protection of the herd needed to suppress the pandemic, we can achieve an antibody-assisted approach more quickly.
Here’s another reason why an antibody-assisted approach to vaccination is needed: Due to the combination of inadequate testing and asymptomatic infection, most people infected with Covid-19 are never diagnosed with it. This is especially true in countries hardest hit by the virus. In the state of New York, for example, it is estimated that 30% of the population recovered from Covid-19, while only 7% were diagnosed with the virus. Underdiagnosis is not limited to locals like New York, who are living early. It is estimated that more than 36% of North Dakotans are infected, while only 13% have been diagnosed. Given these inconsistencies, in states like North Dakota, without the help of antibody testing, I estimate that as many as 1 in 4 vaccines can be given to someone who is currently immune to Covid-19.
Although the presence of antibodies is not a perfect measure of immunity, those with antibodies, due to the rare reinfection and the accuracy of the current antibody test (with false positive doses about 1% or less), may be at low risk be considered. group. This reality was further confirmed in a recent New England Journal of Medicine report from the University of Oxford which followed 12,000 health workers for six months and found no symptomatic infections in those with antibodies to SARS-CoV-2.
But theory and practice are two different things. With the difficulty the U.S. has faced with PCR testing, and with early spray distribution of vaccines, attempts to test levels of the public on antibodies can be foolish. It’s not.
Regarding the scaling down of antibody testing, the process is completely different from the PCR-based testing used to detect acute infection. Antibody tests are more like traditional blood work and are processed as automated immunoassays. This means that they can be managed in large quantities on machines, almost all functional medical laboratories already owned, and that they can use the existing laboratory collection infrastructure for collection and processing. As Benjamin Mazer, a pathologist at Johns Hopkins Hospital, told me: ‘The delays we experience with PCR tests should not deter people from taking antibody tests when necessary. The antibody test is much simpler to perform and can be converted within hours instead of days. ”
An easy place to start is to test for antibodies in people who already need laboratory tests for other reasons, such as when they are admitted to a hospital, in the emergency department or have a clinical appointment. Permanent orders coupled with canceled refunds for others at clinical and commercial laboratories may further expand access. School and employer-based group tests can inform their future vaccination campaigns.
To be clear, it is safe and beneficial for those previously infected with SARS-CoV-2 to be vaccinated (just as adults with chickenpox need a booster to prevent shingles). It is important to invest properly to support both tests. and vaccination. These efforts should be complementary, not competitors. And if access to antibody testing is not easily accessible, vaccination should never be delayed. Finally, if we have enough stock to meet public demand, everyone should be vaccinated, regardless of antibody status.
I can conclude with an argument about how an antibody-assisted approach will enable the US to achieve herd immunity faster. Or make our economy revive faster. Or protect more frontline workers – nurses, teachers, groceries, delivery managers, firefighters and others – sooner.
But for me, and I suspect it for you too, it is much less abstract than that. For every vaccine we save by using antibodies, there will be another one that we can give to a higher risk individual who is anxiously waiting for her or his turn. And we all have loved ones standing in line: an elderly grandparent, a mother with an immune system or a cousin fighting cancer.
Given everything we have done so far to keep it safe – postponed meals, canceled holidays and missed hugs – we must use every weapon in our armory against this plague. This includes antibody testing.
Michael Rose is a family physician in internal medicine and pediatrics at Johns Hopkins University School of Medicine.